The purpose of this study was to examine methods of saliva collection, transportation and microbiological analysis for S. mutans and lactobacilli, which could be adapted to field situations where on site screening is not possible. Experiments were carried out to evaluate the following: 1) The effect of quick freezing and rapid thawing of whole saliva on bacterial counts. This method is applicable to field situations where large numbers of samples are collected over several days and shipped to the laboratory for sequential processing. The average drop in counts after 30 days was 5% for S. mutans and 8% for lactobacilli, indicating that on site freezing of whole saliva is a practical approach for this type of study. 2) The use of a mouth rinsing procedure to facilitate saliva collection yielded counts within the range of variation of whole saliva counts. 3) The effect of combining the saliva rinse with Reduced Transport Fluid for shipment to the laboratory in situations where on site freezing is not possible. S. mutans counts dropped less than 0.1 log10 units after 3 days in RTF, but lactobacillus counts were less predictable, suggesting other transport media should be evaluated. 4) Comparison of three selective media (MSB, GSTB, TSY20B) for recovery of S. mutans. Results vary from sample to sample, possibly due to strain differences, and suggest the use of more than one selective media for S. mutans recovery.